Rocking fulcrum for adjustable and pivotal outer wrench jaws



ATTORNEY June 5, 1951 o. A. cAPRA RooxING FULCRUM FOR ADJUSTABLE AND mom. VOUTER WRENCH JAws Filed March l0, 1948 Patented June 5, 1951 BOOKING FULCRUM FOR ADJUSTABLE AND PIVOTAL OUTER WRENCH JAWS Ottavio A. Capra, Jamaica, N. Y.

Application March 10, 1948, Serial No. 14,095

3 Claims.

An object of the invention is to provide a novel fulcrum for an adjustable and pivotal wrench jaw, the fulcrum including upper and lower arcuately slidable blocks, an adjusting nut positioned between the blocks, and a spring interposed between the nut and the lower block in order to prevent accidental rotation of the nut.

Other objects of the invention will become apparent from the following description of a preferred embodiment thereof, reference being had to the accompanying drawing in which:

Figs. 1 and 2 are a side and a rear elevation, respectively, of a pipe wrench according to the invention;

Fig. 3 represents, on a larger scale, a fragmentary cross-sectional elevation taken on line 3-3 of Fig. 2, showing the nut, rocker and nut Spring assembly with the hook jaw and loading spring removed;

Fig. 4 is a transverse cross section taken on line 4-4 of Fig. 1;

Fig. 5 is a transverse cross section taken on line 5-5 of Fig. l;

Figs. 6, 7 and 8 are a top, side and front view,

respectively, of either of the rocker members shown in section in Fig. 3;

Figs. 9, 10 and 11 are a top, side and front view, respectively, of the nut spring shown in section in Fig. 3

Figs. 12 and 13 are fragmentary side elevations, showing certain modications of the lower jawof the wrench; and

Fig. 14 is a View similar to Fig. 4 but with the hook jaw and rocker assembly removed, showing a modification of the yoke member forming the support for said jaw and rocker assembly.

The principal parts of the pipe wrench I2 shown in the drawing are a handle I3, supporting the lower or stationary jaw I4, a yoke I5 containing the nut, rockers and spring assembly I6, and the upper or hook jaw I1 supported on the yoke I5 by means of the assembly I6. The assembly I6 comprises, in turn, an upper rocker member I8, a lower rocker member I9, a nut 28 and a nut spring 2|, these various elements coacting with one another and with the threaded shank 22 of hook j'aw Il in a manner presently to be described.

The handle I3 is a hollow piece of tubing or casting which comprises an upper portion I3a of elongated, roughly elliptical cross section (Fig. 4) and a lower portion I3b of circular cross section (Fig. 5), the two portions being separated by a dividing line 23 above which a gradual transition from the conguration shown in Fig. 5 to that shown in Fig. 4 takes place. The greater part of lower portion I3b has a knurled surface, as shown at 24, to alford a better grip for the user.

The handle portion I3b terminates in a flattened end portion 25, the latter being preferably provided with a hole 5I serving to suspend the wrench from a hook or nail when not in use.

The peculiar shape of handle I3 furthermore enables portion I3a thereof to support the lower jaw I4 without the provision of any special fastening means therefor. As best seen in Fig. 3, the jaw I4 is provided with a depending portion or stem 26 which penetrates a certain distanceinto handle portion I 3a, the toothed upper portion Ma of the jaw simply resting on the upper rim of the handle. Stem 26 fits snugly into handle portion I3a, as shown in Fig. 4; if desired, however, the jaw I4 may be readily withdrawn from the handle and just as simply reinserted or replaced.

The yoke I5 comprises a frame having two aligned circular cutouts 21, 28, the frame being preferably of oblong, rounded-off cross section generally similar to that of handle portion i3d, and partly embracing the latter as shown in Fig. 4. Frame member I5 forms a vertical channel 29 just Wide enough to accommodate the shank 22 of hook jaw Il, this shank being preferably provided with opposite longitudinal tapered grooves 3U, 3l to reduce weight and friction. Threads 32 on shank 22 are in engagement with threads 33 of nut 20, the latter projecting through the cutouts 2'I, 28 but being held clear of the frame I5 by means of rockers I8, I9 and spring 2l. The two rockers being identical in construction, only one of them, the upper rocker I8, is shown in detail in Figs. 6, 7 and 8.

The rocker I 8 comprises a circular base 34 formed with a roughly rectangular cutout 35 whose width corresponds to that of channel 29 in yoke I5. The cutout 35 is bounded by two segmental ridges 36, 31 having a radius of curvature which equals the radius of circular cutouts 2l, 28 in yoke I5. Ridges 36, 31 register respectively, with the side walls 38, 39 of the yoke I5 when the members I8, I3, 20, 2| and 22 are operatively assembled, nut spring 2| serving to insure continuous contact between these ridges and adjacent portions of these side walls.

Referring to Figs. 9, 10 and 11, it will be seen that the spring 2l comprises a resilient annular member 40 formed with a cutout 4I which registers with cutout 35 in rocker I8 and the corresponding cutout in rocker I9, except for Vrecesses 42 of small radius provided at each of the four corners of cutout 4I. The purpose of these recesses is to provide clearance between the spring 2| and the corners of thread 32 so as to prevent any jamming action in the event of misalignments of the spring relative to the shank 22. Spring 2l is further provided with four depending tags 43 which resiliently engage the base 34a of lower rocker I9, as best seen in Fig. 3, whereby longitudinal displacement of the spring 2l sufficient to interfere with the movement of the threaded shank 22 will be prevented. By bearing upon the nut 20, spring 2l also prevents spontaneous rotation of this nut whereby the wrench will be forced to retain a given setting,

From Fig. 1 it will be seen that the Vtoothed portion Ila of hook jaw I'I extends at an angle greater than 90 relative to the shank 22, even as the toothed portion Ida of lower jaw I4 is inclined toward the horizontal in the opposite sense. This arrangement makes it possible to grip for example, a pipe and a fitting or union connected thereto without intervening manipulation of the nut 20. ln order to insure secure gripping of the work piece by the jaws I4, il in spite of their uncommonly wide angle of opening, a loading spring 44 bears upon the shank 22 above the pivoting center assembly I6, Vthus tending to rock the hook jaw il Vinto closing po* sition.

The spring 44 preferably consists of a resilient blade having a gooseneck portion at l5 which engages the rear wall 4l of yoke l5 from underneath, this wall beingl provided with a hole i3 into which enters a tag 49 formed at one ex'- tremity of spring 54. The other extremity 46 exerts pressure upon the hook jaw Il. It will be seen that the loading spring 40 may be placed in position by simply introducing portion 46 thereof into the channel 38 from below, to the rear of pivot assembly I6, and inserting the tag 49 into the hole 48, no further anchorage as by riveting or other fastening methods being required.

The yoke I5 is preferably secured to handle portion 13a by spot welding. For this purpose, the walls 38, 39 of the frame forming the yoke may be provided with a plurality of projections.

50 to insure good conductive and mechanical contact at the points where welding is to take place;

Fig. '12 illustrates a modiiication of the lower jaw or heel plate, indicated here at IIA, designed to provide a better grip on stock of certain sizes. The teeth of this jaw IIA are arranged along a convex surface, the radius of curvature being selected so that pieces of stock 52 will be more effectively accommodated by positioning them adjacent the vertical shank of hook jaw I'I, as illustrated.

A particularly improved accommodation of pipes and companion mate fittings especially for larger sizes may be obtained by designing the stationary jaw in the manner shown at 2I4 in Fig. 13. Here the heel plate comprises a horizontal portion 2I4a. which, therefore, extends at right angles to the'axis of the handle I3, as well as an inclined front portion 2Mb enclosing an angle of less than 90 degrees with said axis. The latter angle may be substantially the same as that of heel plate I4a,'Figs. 1 and 3.

Fig. 14 illustrates a yoke member II5 which is a modification of yoke I5, Figs. l, 3 and 4, in that the sides thereof do not close around the handle portion I3a but remain spaced apart to provide a substantially U-shaped cross section. This en- 4 ables the member I I5 to be stamped and pierced, thereby greatly simplifying the manufacturing process, and reducing the cost of the entire wrench.

Although the invention has been described and illustrated with particular reference to a single, now preferred embodiment, it is to be distinctly understood that various modifications and adaptations lare within reach of persons skilled in the 10 art and may be carried out without departing 15 1. In a pipewrench, in combination, a handle,

a Yfixed jaw supported on said handle, .a hook jaw comprising a threaded shank, and pivot means supporting said shank in a position offset from and roughly parallel to said handle, said pivot 20 means including a yoke member secured to said handle, said `yoke member being formed with a channel to receive said shank and further having a pair of co-extensive circular cutouts communicating with said channel at opposite sides thereof, a nut surrounding said shank Vand `extending into said cutouts, a pair of oppositely disposed segmental rocker members each sur# rounding said shank above and below said nut, respectively, said rocker members being each slidably held in both of said cutouts, and a bowed plate spring surrounding said shank intermediate said nut and one of said rocker members, said spring moving jointly with said rocker members and with said nut inside said cutouts, whereby both of said rocker members will be forced firmly against said yoke member and spontaneous'rotation of said nut will be prevented.

2. The combination according to claim 1, wherein said shank is formed substantially rectangular in cross section and said spring is provided with an approximately rectangular cutout, each of the corners of said cutout being recessed to provide clearance between said spring and the corners of said shank.

3. The combination according to claim 1, wherein said spring is provided with a plurality of depending tags resilientlyengaging the adjacent rocker member to prevent substantial relative displacement between said spring and said adjacent rocker member.

` OTTAVIO A. CAPRA.

REFERENCES CITED UNITED STATES PATENTS l Number Name Date 197,658 Ochsner Nov. 27,1877 549,221 Wenger Nov, 5, 1895 1,026,040 Hyle May 14, 1912 1,143,350 Benedict June 15, 1915 1,288,969 OConnor \Dec. 24, 1918 1,360,672 OConnor Nov. 30, 1920 y 1,389,581 Dies Sept. 6, 1921 1,602,619 Larson Oct. l2, 1926 1,778,748 Bayrer Oct. 21, 1930 2,211,507 Lilleberg Aug. 13, 1940 FOREIGN PATENTS Number Country Date 346,271 France Jan. 10, 1905 479,363

Great Britain Feb. 4, 1938 

